CHARACTERISTICS OF LIFE 1) 1)LIVING THINGS ARE MADE FROM THE SAME BUILDING BLOCKS, ORGANIZED INTO CELLS

LEVELS OF ORGANIZATION atoms molecules  nonliving = abiotic cells  living = biotic tissues organs organism = living thing Human Brain Nerve Cell

ORGANISM = living thing   Species = similar organisms, interbreed in the wild, only with each other   Species = reproductively isolated group of organisms   Species = one kind of organism

  population = all members of the same species, that live together in same area, at same time   community = all populations (plants & animals) that live together in same area, at same time physical environment = non living (abiotic) air, rocks, soil, water, light, climate   ecosystem = community + physical environment   biosphere = all organisms on Earth = all communities on Earth = all life on Earth

CHARACTERISTICS OF LIFE 2) ORGANISMS GROW & MAINTAIN THEIR ORGANIZATION BY GETTING MOLECULES & ENERGY FROM THE ENVIRONMENT

= self feeding Autotrophs = self feeding Energy Flow: Sunlight  Food Molecules  Work  Heat  Heat = plants, algae, some bacteria

Heterotrophs = other feeding (eaters) = animals, fungi, bacteria Energy Flow: Food Molecules  Work (stay organized) (to atmosphere)  Heat (to atmosphere)

CHARACTERISTICS OF LIFE 3 ) ORGANISMS MOVE OR OTHERWISE RESPOND TO CHANGES (STIMULI) IN THE EXTERNAL ENVIRONMENT Response = Behavior

CHARACTERISTICS OF LIFE 4 ) ORGANISMS REPRODUCE & PASS ON THEIR DNA TO THEIR OFFSPRING DNA = Instructions

CHARACTERISTICS OF LIFE 5) GROUPS OF ORGANISMS SHOW VARIATIONS & EVOLVE, OR CHANGE, TO ADAPT TO THEIR ENVIRONMENT Source of variations = mutations, which are changes in DNA and new combinations created by sexual reproduction

Evolution = changes in a population over time Natural Selection = nature selects the changes

LIFE MODEL Survival = First Priority for Resources Is Stay Alive Growth = Extra Resources must be available Reproduction = Extra Resources must be available

Science SCIENCE = derived from a Latin verb meaning “to know” = seeks natural causes for natural phenomena Includes two forms of inquiry; 1) Discovery (descriptive) science 2) Hypothesis-driven science

Discovery Science Observations of nature Human genome project Inductive conclusion is a generalization based on many specific observations Ex. “All organisms made of one or more cells”

Hypothesis-driven Science Scientific Method = series of steps that form a formal process of inquiry Deductive conclusion is using the general premise to predict a specific result Follows “if…then” logic, i.e. if all organisms are made of cells, & humans are organisms, then humans are made of cells.

HYPOTHESIS Can be shown to be false Can NOT be proved true, only supported by results Example: I am the fastest runner in the world

Fly Mimicry Experiment OBSERVATIONS Jumping Spiders 1) 1)stalk and pounce on flies 2) wave their legs to scare off other jumping spiders Jumping Spider

Fly Mimicry Experiment OBSERVATIONS Spider-mimicking flies 1) have markings on their wings that look like spider’s legs 2) wave their wings (false legs) at spiders

Fly Mimicry Experiment QUESTION #1 Does mimicry (looking like jumping spiders) actually turn real jumping spiders away?

Fly Mimicry Experiment HYPOTHESIS Mimicry (looking like jumping spiders) does turn real jumping spiders away.

Fly Mimicry Experiment Control Group (of organisms) = Normal Spider-mimicking flies Experimental or Treatment Group (of organisms) = Flies with wing markings or “legs” masked

Fly Mimicry Experiment Manipulated or Independent Variable = difference between two groups that is being tested = looking like jumping spiders

Fly Mimicry Experiment Responding (Dependent) Variable = results that may be different between the two groups being compared Responding (Dependent) Variable = Pounce rate (% of trials in which spiders jumped on the fly)

Fly Mimicry Experiment Controlled Variables or Constants = all factors that are the same between the two groups

Fly Mimicry Experiment Results = spiders pounced on treatment group more than controls, as shown on graph Conclusion = the results support the hypothesis that mimicry (looking like jumping spiders) did turn jumping spiders away

Fly Mimicry Experiment OBSERVATIONS Jumping Spiders 1) 1)stalk and pounce on flies 2) wave their legs to scare off other jumping spiders Jumping Spider

Fly Mimicry Experiment OBSERVATIONS Spider-mimicking flies 1) have markings on their wings that look like spider’s legs 2) wave their wings (false legs) at spiders

Fly Mimicry 2 nd Experiment QUESTION #2 Are both types of mimicry; (acting & looking like jumping spiders) required to turn real jumping spiders away?

Fly Mimicry 2 nd Experiment HYPOTHESIS Both types of mimicry (acting & looking) like jumping spiders) are required to turn real jumping spiders away.

Fly Mimicry 2 nd Experiment Manipulated Variables = difference between two groups that are being tested Mimicry = looking like jumping spiders = wing markings Mimicry = acting like jumping spiders = wing waving

Fly Mimicry 2 nd Experiment Five Test Groups of Flies 1) Normal spider mimics 2) Mimics w/ mimic wing transplants 3) Mimics w/ housefly wing transplants 4) Houseflies w/ mimic wing transplants 5) Normal houseflies

Fly Mimicry 2 nd Experiment Dependent Variable = results that may be different between the two groups being compared Dependent Variable = actual number of stalk and attack responses by spiders

Fly Mimicry 2 nd Experiment Results = spiders stalked and attacked groups without both types of mimicry more often than groups with both types Conclusion = the results support the hypothesis that both types of mimicry (acting & looking like jumping spiders) are required to turn jumping spiders away

According to the National Academy of Sciences, Some scientific explanations are so well established that no new evidence is likely to alter them. The explanation becomes a scientific theory. In everyday language a theory means a hunch or speculation. Not so in science. In science, the word theory refers to a comprehensive explanation of an important feature of nature that is supported by many facts gathered over time. Theories also allow scientists to make predictions about as yet unobserved phenomena. Scientific Theory According to Stephen Hawking, "a theory is a good theory if it satisfies two requirements: It must accurately describe a large class of observations on the basis of a model which contains only a few arbitrary elements, and it must make definite predictions about the results of future observations".

Isaac Newton's theory of universal gravitation is a physical law describing the gravitational attraction between bodies with mass. It states the following: Every object attracts every other object by a force pointing along the line intersecting both objects. The force is proportional to the product of the two masses and inversely proportional to the square of the distance between the objects. Is it supported by many facts gathered over time? Does it allow scientists to make predictions about as yet unobserved phenomena?